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Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund Integration of different metrics to a whole water body classification for all.

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Presentation on theme: "Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund Integration of different metrics to a whole water body classification for all."— Presentation transcript:

1 Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund Integration of different metrics to a whole water body classification for all water bodies in WEL catchment Jannicke Moe (NIVA) deWELopment project meeting 22.06.2010, Oslo

2 Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund Outline What does the WFD require? The one-out all-out principle The role of uncertainty Alternatives to OOAO

3 Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund What does the WFD require?

4 Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund Integration process for elements recommended by the CIS ECOSTAT WG (modified from EC, 2005)

5 Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund This presentation: focus on BQEs Assessment for whole waterbody

6 Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund Macroinvertebrates Phytobenthos Hydrology Acidification Organic Example: With data from one waterbody, we have calculated metrics and assigned ecological status class for: -12 metrics - 4 pressures - 2 BQEs How can we combine information from the 12 metrics?

7 Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund The ”One-Out All-Out” principle

8 Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund Macroinvertebrates Phytobenthos Hydrology Acidification Organic Combining metrics and BQEs

9 Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund The ”One-Out All-Out” principle The EC recommends to apply the “One-Out All-Out” (OOAO) principle for aggregation at QE level: –when all BQE are classified, the ecological status is initially determined by BQE with the lowest class –if a supportive QE indicates a worse situation than the BQEs, the ecological status is downgraded to the supporting QE’s class. From deWELopment project description: “The applicability of the one-out-all-out principle recommended in the WFD Classification guidance (2005), is questioned by many scientists, and alternative methods for holistic assessment may be needed to obtain acceptable confidence and precision in the classification result.“

10 Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund Limitations of the OOAO principle OOAO always selects the “worst case” – but the worst case may sometimes have been assigned too low class by error –E.g. “p-value <0.05”  we accect 5% error rate More uncertainty in metrics: –  higher risk that some measured metrics value is too low (and others too high) –  OOAO can result in too low class Higher number of metrics and/or BQEs used in classification: –  higher risk that some measured metrics value is too low (and others too high) –  OOAO can result in too low class

11 Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund The role of uncertainty

12 Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund Calculation of uncertainty -Uncertainty within station: - StDev of samples -Uncertainty within BQE: -pooled stdev of stations sqrt(avg(stdev^2)) -Uncertainty within WB: -StDev of selected BQE? 0.45 (?) Example: Randomised EQRs for 3 samples x 3 stations x 3 BQEs Lowest EQR Highest uncert. Determines class Highest EQR Lowest uncert. Ignored

13 Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund 0.45 (?) Handling of uncertainty -Aggregation of StDevs (or other uncertainty measures) can be complicated Probabilistic approach : -Calculate the probability of each status class -Aggregate probability distributions to WB level -Bayesian Network -Weight-of-Evidence appr.

14 Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund Alternatives to OOAO

15 Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund From the deWELopment project description: We will test different methods of combination of these single metric results to obtain a total result at the whole element level, taking into account the uncertainty in the different single metrics –one-out-all-out principle –simple averaging –weighted averaging –multimetric approach Additional suggestions: –probabilistic approach –Weight-of-Evidence framework

16 Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund ”Weight-of-Evidence approach” Combines information from multiple lines of evidence to reach a conclusion about an environmental system or stressor (Chapman et al. 2002, Burton et al. 2002). Combines analysis of field data (to determine patterns) with experimental hypothesis testing (to determine mechanisms) to make prediction of the future effects and provide appropriate management recommendations (Lowell, 2000)

17 Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund MODELKEY: WoE-based WFD classification tool

18 Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund MODELKEY example: WoE vs. OOAO OOAO rule: WoE alternative:

19 Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund MODELKEY example: multiple pressures per BQE

20 Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund Macroinvertebrates Phytobenthos Hydrology Acidification Organic Example: Combining metrics and BQEs OOAO rule: each 25% 0% 100% WoE alternative: each 25% 20% 60%

21 Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund Recommendations for deWELopment

22 Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund Assessment of within-BQE uncertainties Follow recommendations from WISER WP6.1 Uncertainty Workshop (September 2010) Communicate with WISER WP6.1 in advance

23 Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund Integrating BQE values and uncertainties In addition to OOAO: Try a simplified weighting approach based on the MODELKEY principles and tools Decide on weighting of different metrics and BQEs: –Use expert judgement More sensitive element / metric  higher weighting –Use uncertainty estimates from deWELopment data higher uncertainty  reduced weighting Compare outcome of OOAO vs. WoE approaches on classification of deWELopment waterbodies

24 Polsko-Norweski Fundusz Badań Naukowych / Polish-Norwegian Research Fund Discussion!


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